computer science

Test assertion

Test assertion is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Test assertion rather than just read about it. In short: In computer software testing, a test assertion is an expression which encapsulates some testable logic specified about a target under test. The expression is formally presented as an assertion, along with some form of identifier, to help testers and engineers ensure that tests of the target relate properly and clearly to the corresponding specified statements about the target.

Key takeaways

Test assertion belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Test assertion to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Test assertion from memory before moving on to harder problems.

Reference excerpt

In computer software testing, a test assertion is an expression which encapsulates some testable logic specified about a target under test. The expression is formally presented as an assertion, along with some form of identifier, to help testers and engineers ensure that tests of the target relate properly and clearly to the corresponding specified statements about the target. Usually the logic for each test assertion is limited to one single aspect specified. A test assertion may include prerequisites which must be true for the test assertion to be valid.

See also Test driven Conformance testing

References

Green, Stephen D. (Editor) et al. (2012) "Test Assertions Guidelines Committee Note 1.0" OASIS-open.org Durand, Jacques et al. (2009) "Test Assertions on steroids for XML artifacts." In Proceedings of Balisage: The Markup Conference 2009. Balisage Series on Markup Technologies, vol. 3 (2009)

External links [1], W3C 'Test Assertion Guide' (Editor's Draft) [2], Unisoft's 'Glossary of Testing Terms' includes a definition for 'test assertion' [3], OASIS-open.org has a technical committee producing open, royalty-free specifications for a test assertions model and markup language

Worked examples

Example 1 — a first encounter with Test assertion

Start with the simplest possible case. Write down what Test assertion claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Test assertion before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Test assertion ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Test assertion

In research: Test assertion appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Test assertion in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Test assertion is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computing stubs, Software testing, so understanding it makes those chapters shorter.
In everyday life: Look for Test assertion outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Test assertion in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Test assertion means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Test assertion out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Test assertion in simple terms?

Why does Test assertion matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Test assertion?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Test assertion.